Make various gfx classes more amenable to use as compile-time constants.

cc/test/layer_test_common.cc

Index: cc/test/layer_test_common.cc
diff --git a/cc/test/layer_test_common.cc b/cc/test/layer_test_common.cc
index ea49f5f1eab3832ea6b890dc2dd5c037613af001..d5c5a1c9d24314d51fb1baa1f183047b2cf71dae 100644
--- a/cc/test/layer_test_common.cc
+++ b/cc/test/layer_test_common.cc
@@ -97,8 +97,6 @@ void LayerTestCommon::VerifyQuadsAreOccluded(const QuadList& quads,
       // ends up on integer boundaries for ease of testing.
       ASSERT_EQ(target_rectf, gfx::RectF(target_rect));
     }
-    gfx::Rect target_visible_rect = MathUtil::MapEnclosingClippedRect(
-        quad->shared_quad_state->quad_to_target_transform, quad->visible_rect);
 
     bool fully_occluded_horizontal = target_rect.x() >= occluded.x() &&
                                      target_rect.right() <= occluded.right();